Control means for light signals



J. A. PEABODY CONTROL MEANS FOR LIGHT SIGNALS Original Filed Jan. 24.1924 Quorum I Patented May 3, 19.27.

UNITED. STATES PATENT I OFFIQE.

JAMES A. PEABODY, or nvnnsron, ILLINOIS, nssrelvon. r GENERAL RAIL'WAYSIGNAL COMPANY.

CONTROL MEANS FOR LIGHT SIGNALS.

Original application filed January 24, 1924, Serial No. 688,238. Dividedand this application filed October This invention relates to railwaysignaling and more particularly concerns a checking or safety means foruse in'connection with railway signaling systems of the color lighttype.

In the en'iployinent of multiple aspect color light signals there isalways an uncertainty as to whether the signal gives an indication atall, since incandescent electric l0 lamps are preferably used and thelight of such lamps is uncertain due to the limited life of thefilament, so that a signal at times may not give an indicationat all.For instance, since the most common indication of W the signal is clear,the lamp for the clear signal unit is most apt to burn out first becauseitis burned more than the lamps for the other indications. If the clearlamp should burn out, no indication would be given by the signal at all;and although this condition might be taken as a danger signal, it mayhappen that the engineer would not notice the passage of a signallocation, and thereby run into a block already occupied.

With the above and other considerations in mind, it is proposed, inaccordance with. the present invention, to provide suitable automaticmeans whereby if a lamp burns out another lamp of equal or a morerestric- F tive signal indication is illuminated. More specifically itis proposed to have thecaution lamp automatically cut into an energizedcircuit when the clear lamp burns out and clear traiiic conditionsprevail, so that a caution signal will be given instead of a darksignal;

Other objects, purposes and characteristic features of the inventionwill appear as the description progresses.

in describing the invention in detail, reference will be made to theaccompanying drawing, in which a single figure has been shown, being adiagrammatic view of a portion of a railway system employing multipleaspect color light signals which are con trolled in a manner toautomatically cut in a caution lamp when the clear lamp is burned out.

This application is a division of my oopending application, Serial No.688,238,

filed January 24th, 1924.

Referring to the drawings, there has been shown a track to which signalsembodying the present invention have been applied.

Serial N0. 63,376.

This track apparatus comprises rails 50 divided by insulating joints 51into blocks in the usual manner, the block I and the ad jacent ends oftwo other. blocks H and J being shown. Each of the blocks is providedwith a suitable source of energy at its exit end, which has beenconventionally illustrated by the battery 52, and is provided at theentrance end with a track relay T. Since the various blocks are thesame, like parts of each block will be assigned like referencecharacters having distinctive exponents. Each .of the blocks is providedwith a line relay .L which is energized by reason of the front contacts53 of the track relay of the block at the entrance to which it is placedand the front contact 54 of the track relay of the block next in advancewhile these blocks are unoccupied.

Suitable multiple aspect wayside signals, are located atthe entrance endof each bloclr. These signals are illustrated in a conventional manneras color light signals of the type employing incandeszent electric lampsin suitable casings having distinctive color screens, usually coloredgreen, yellow, and red to represent clear, caution, and danger traflicconditions respectively. Although a particular type of wayside signalhas been shown, it should be understood that any other type of colorlight or other wayside signal in which tie indication of a given traliiccondition is accomplished by means of closing an electric circuit mightbe employed.

Clear indication.Referring more particularly to the block I, the greenor clear lamp G is energized under normal traflic conditions aheadthrough a circuit which may be traced as follows: beginning at theterminal B of a suitable source of energy which has its other terminalconnected to a common return wire C, front contact 55 of the track relayT, wire 56, front contact 57 of the line relay L, wires 58 and 59,winding of the check relay CR, wire 60, clear lamp Gr, wires 61 and 62,back to the common return wire C. The energizing current for the lamp Gflowing through the check relay GR is sufficient to cause this relay toassume its energized p0sition, thereby opening its back contact 63. Thischeck relay CR maybe of any desired construction, provided that it issensitive enough to be energized by the current flowing in the lamp GWithout introducing a prohibited amount of resistance in the circuit.

Caution indications-Jr the block J should be occupied for any reason,the track relay T assumes its tie-energized position, drops its frontcontact 54 and tie-energizes the line relay L. The de-energization ofthe line relay L causes its contact 57 to drop, thereby closing acircuit for the caution or yellow lamp Y which may be tracedas-t'ollows: beginning at the terminal B. contact 57 in its lowerposition, wires 64 and 65, impedance unit 66, wire 67, caution lamp Y,wires 68 and (52, back to the common return wire C. It is thus notedthat the caution lamp 1' at the entrance to the block I is energizedwhen the block J is occupied.

Danger indication.-If now the block I is occupied by a train, or is indanger for some other reason, the t 'ack relay T assumes its deenergizedposition for obvious reasons. This causes the contact 55 of the trackrelay '1 to assume its lower position, thereby closing a circuit for thered or danger lamp R which may be traced as follows: beginning at theterminal B, contact ot the track relay T in its lower position, wire 70,impedance unit 71, wire 72 danger lamp R, wire 73, back to the commonreturn wire C.

("caution indication under clear conditions. Let us assume that theblock I and the block J are both unoccupied and that the relays T and Tassume the energized. position thereby completing a circuit "for theclear lamp (l. as heretofore traced. Let us assume now that the clearlamp burns out so that it is extinguished and the energizing currentwhich heretofore was flowing in the check relay CR has been interrupted.This can-es the check relay (R to assume its decnereized position,thereby completing a circuit for the yellow lamp Y, which may be tracedas follows: beginning at the terminal ll. 'l'ront contact 55 of thetrack relay T.

he 56, front Contact 57 of the line relay l). wires 58 and T l. ba kcontact (53 of the check relay CR, wire 75, front contact 76 of thelinere-lay L, wires '77 and (S5, impedance unit (56, wire (57, yellowlamp Y. wires (as and (52. to the common return wire C. It. is thusnoted that failure ot the energizing circuit tor the clear lamp G,probably because the filament of this lamp has burned out. causes thecaution lamp Y to be energized instead, thus giving, a caution signaland allowing the engineer to proceed instead of having no signal toguide, advise or protect him against possible danger ahead.

The impedance units 66 and 71 have an impedance approximately equal tothat of the resistance of the check relay CR. These impedance units areemployed so that the incandescent lamps used in the signals G, Y, and R,respectively, may be of the same candle power and cu rent carryingapacity and may be interchanged it desire-l. t. should be noted that notonly failure of the filament of the lamp (l :auses the lamp Y to beenergized instead. but that Failure oi the winding of the control relay(fl-L, either because it open or because it is hunted. ca cnergzjizationoi the caution lamp In the particular arrangement of tract: circuitsEllOWll the clear lamp l only has bee protected against open circuits bythe check relay CR by energizing the caution or lamp Y instead of clearlamp ll should. however, be understood that the same arrangement may beapplied to the cautirm lamp Y by providing a similar check relay inseries with such caution lamp and providing a back contact whichcompletes a circuit for the red lamp it when :"uch caution lamp isdeenere'izcd; also. the same :zrrangre ment may be applied to the redlamp it by providing another auxiliary red lamp which is energized itthe red lamp of the. signal is burned out or its energizing circuit isopen for some other reason, the same arrangement being appli able tolamp G and i.

As already stated. the green or clea the clear or green light shouldburn out under clear trailic conditions. a so-ralled dark signal is theresult; and while such a dark signal. according to the rules, riginitiesstop, the engineer may fail to observe the signal making it desirable touse an a-lditional marker lamp to locate the signal. This inventionprovides, however, for cutting in and lighting the yellow or cautionlamp whenever th green or clear lamp burns out, thereby prm'irlim areserve indication for the Q'reen indicafion which not. only serve thepurpose of a lurker light but also is more likely to assure sate controlof the train. It is mnsidered preferable to cut in the yellow or cautioninr'lication upon burning); out of the green lamp. rather than cutting);in a reserve lamp for the green si nal, because the engineer underOl'fllllllf circumstances would observe the showing ot a caution indicaton instead of a lear in dication and would report the abnormalcondition, n'iaking; prompt repair more certain than it a green. lamp inreserve is used. On the other hand it the signal in (question anapproach signal where the yellow or caution lamp is burning almostcontinually it is considered preterable to have an auxiliary lampgiving: the same distinrtiyc indication when such caution lamp burnsout. If desired, additional resistance may be cut in series with theyellow amp when lighted because oi 't'ailure of the green lamp. to as togive weaker caution indication and show llll ltlll the engineer thatsomething is out of order; but ordinarily the engineer would be able todetect the showing oi a yellow light Where a green lamp should bedisplayed.

Although the invention has been shown applied to a color light signal.it is desired to be understood that it may also be applied to positionlight signals, where a group of ligli are used to define a bar or signalblade the position of which determines the signal indication.

liai'iiur thus shown one specific embodiment oi? the nes-cut inventionand the manner in which it may be applied to one particular type oftrackway apparatus and associated relays, it is desired to be understoodthat various changes, modifications, and alterations maybe made to adaptthe invention to any other system and the various conditions encounteredin practice Without departing from the spirit of the invention or theidea of means underlying the san'ie.

What is desired to be secured by Letters Patent ot the United States isp l. A multiple aspect light signal for railroads coni 'irising, a firstlight projecting unit including an incandescent lamp, a lighting circuitand control means for said lamp, a relay in said lightingrcircuit in seres with the filament ot the lamp, a second light projecting unit givinga distinctive indication different from that 01. the first unit, and alighting circuit and control means for said second unit which latterlighting circuit is energized independently of its control means uponde-energization o f said relay provided the lighting circuit of thefirst unit is closed at its controi means.

2, A. light signal for railroads, comprising two light projecting unitsgiving different signaling aspects, an incandescent lamp for each unit,a lighting circuit and control means tor-each lamp, and automatic meansassociated with the lighting circuit of one lamp for lighting the otherlamp independently of its control means, said automatic means beingeiiective whenever the lighting circuit of the first mentioned lamp isestablished. and current fails to flow therein.

3. An autoi'i'iatic block signal system for railroads comprising, arailway track divided into blocks by insulating joints, a multiple unitcolor light signal at the entrance to each block including a clear lightsignal unit and a caution light signal unit, a circuit for said clearlight signal unit including the Winding of a check relay completed underclear traffic conditions ahead, a circuit for said caution signalunitcompleted under adverse traflic conditions ahead, and meansincluding said check relay tor independently energizing said cautionsignal unit.

t. An automatic block signal system for clear a l ght s in advance areenergized,

railroads comprising, a railway track divided into blocks by insulatingjoints, a multiple unit color light gnal at the entrance to each blockincluding a clear light signal unit and a caution light signal unit, acircuit for said 'gnal unit including the wind ing of a check relaycompleted under clear tratiic coinlitioiis ahead, a circuit for saidcaution signal unit completed under adverse traillic comlitions ahead,and means including a back contact ot said check relay, for energizingsaid caution signal unit under clear traliio conditions ahead it theiilamcnt ot the lamp in the clear signal unit is burned out.

5. An automatic block signal system tor railroads comprising, a railwaytrack divided into blocks by insulating oints, a inultr le unit colorlight si nal at the entrance l bl l l d' 1 l' ht 1 L0 eaci on i morn ina c eai 1 s na unit and a caution light signal unit, a circuit tor saidclear ight signal unit including the winding of a check relay completedunder clear traflic conditions ahead, a circuit ior said caution signalunit completed under adverse traiiic conditions ahead, and means-s torenergizing the lamp of said caution signal under clear trallicconditions ahead when the check relay is deenergized.

6. In an automatic block-signal system, the combination of a trackdivided into blocks having a track relay at the entrance to each block,a line relay, a circuit for energizing said line relay closed it thetrack relay of that block and the track relay of the block a signalcomprising a clear, a caution and a danger lamp, means for energizingsaid clear lamp it both the track relay and the line relay of a blocl;are energized, for energizing said caution lamp if the track relay of ablock is encrgized but the line relay is Clo-energized, and forenergizing the danger lamp ii the track relay is de-energized, said lastmentioned means including means for energizing the caution lamp if thetrack relay and the line relay are both energized and the filament ofthe clear lamp is burned out.

,7. In an automatic block signal system, the combination of a trackdivided into blocks each having a signal com 'irising a clear lamp, acaution lamp and a danger lamp, means for energizing said clear lamp ofthe block if that block and the nextblock in advance are unoccupied,energizing the caution lamp if said block is unoccupied but the block inadvance is occupied, and for energizing said caution lamp if saidbloclrresponding to more dangerous traffic conditions ahead if the filament ofthe other of said lamps fails and traffic conditions are such that itshould be illuminated.

9. In a color light signal, two light projecting units each including anincandescent lamp and giving different signal indications when thecorresponding lamp is lighted, a circuit for each lamp, a controlcontact in one of said circuits, and a relay included in the circuit ofthe other lamp for closing a slnmt for said control contact upondecnergization of said relay.

10. A light signal for railroads comprising, light propecting meanshaving two incandescent. lamps acting to give distinctive signalingindications corresponding to different traffic conditions when therespective lamps are lighted, a relay having cont-acts closed upondeenergization thereof and connected in series with the filament. of oneof said lamps, and a lighting circuit for the other lamp including saidcontacts of said relay.

11. In a lightsignal, the combination with light projecting means havingtwo incandescent lamps and giving distinctive indications when saidrespective lamps are lighted, and control means for separately lightingsaid lamps, and a relay having contacts closed upon dcenergizationthereof, said relay having its winding included in series with thefilament of one lamp, and a circuit includ ing the contacts of saidrelay for lighting the other lamp independently of its control means,whereby said other lamp is automatically lighted if the first lamp failsto light when it should.

12. A light signal and control means therefore comprising, a pluralityof light projecting units each including an in candescent lamp, alighting circuit for each lamp, a relay having contacts closed upondeenergization thereof and having its winding included in one of saidlighting circuits, a current limiting means in each of the otherlighting circuits substantially equivalent to said relay winding formaintaining approximately the same magnitude of current in saidcircuits.

13. In a signaling system for railroads, the combination with a multipleaspect light signal including a plurality of incandescent lamps actingto give distinctive indications corresponding to different trafiicconditions when lighted, of automatic means including a relay havingcontacts closed upon deenergization thereof for lighting the lamp givinga more restrictive indication whenever the lamp giving a more favorableindication fails to light when it should.

l-at. A multiple aspect signal, a circuit and control means for eachsignal aspect, and automatic means associated with the circuit of oneaspect for energizing the circuit of another aspect independently of itscontrol means. said automatic means being effective whenever the circuitfor the one aspect is established and current fails to flow therein.

15. A multiple aspect signal, giving indications of differentrestrictions, a circuit and control means foreach signal aspect, anautomatic means associated with the circuit of a less restrictive aspectfor energizing the circuit of a more restrictive aspect independently ofits control means, said automatic means being effective whenever thecircuit for the less restrictive aspect is established and current failsto flow therein.

16. A multiple aspect light signal for railroads having lamps controlledaccording to trafic conditions ahead, and automatic means independent oftraffic conditions, for lighting a second lamp after a first lamp failsand traffic conditions are such that the first lamp should be lighted.

17. A multiple aspect light signal for railroads having lamps controlledaccording to traffic conditions ahead, and automatic means, independentof trafiic conditions, for lighting a more restrictive lamp if a lessrestrictive lamp fails and traffic conditions are such that. the lessrestrictive lamp should be lighted.

18. A multiple aspect light signal. for railroads having lampscontrolled according to trafiic conditions ahead, and giving yellow andgreen indications respectively, and automatic means, independent oftrafiic conditions, for lighting the yellow lamp if the green lamp failsand traffic conditions are such that the green. lamp should be lighted.

In testimony whereof I affix my signature.

JAMES A. PEABODY.

